The Emperor (皇帝 huángdì) was the sovereign title of the ruler of China. Legitimacy flowed from the emperor: he appointed officials, granted titles, and sanctioned military action. The collapse of Han authority centred on who controlled or could replace the emperor.
Emperor Xian and the late Han
Emperor Xian (劉協) was placed on the throne by Dong Zhuo in 189 and remained emperor until 220. For most of his reign he was a pawn of powerful regents: Dong Zhuo, Li Jue and Guo Si, and then Cao Cao. Cao Cao ruled in the emperor’s name but never took the throne himself.
Three kingdoms, three claims
After Cao Cao’s death, his son Cao Pi received the Han emperor’s abdication and founded the Wei dynasty, becoming Emperor Wen of Wei. Liu Bei declared himself emperor of Shu Han in 221, claiming to restore the Han. Sun Quan took the title King of Wu and later (229) declared himself emperor of Wu. Thus the period ended with three rival emperors and no single recognised Son of Heaven.